Linking ocean conditions to year class strength of the invasive European green crab, Carcinus maenas

Abstract

Once a non-native species arrives and survives in an area, its long-term persistence depends on its recruitment success. If conditions are not favorable for recruitment it will ultimately disappear. The European green crab (Carcinus maenas) has a 6 year life span and has persisted at low densities in Oregon and Washington coastal estuaries for the past 12 years. We show here that after the arrival of the strong founding year class of 1998, significant selfrecruitment to the Oregon and Washington populations occurred only in 2003, 2005 and 2006. Warm winter water temperatures, high Pacific Decadal Oscillation and Multivariate ENSO (El Niño Southern Oscillation) Indices in March, late spring transitions and weak southward shelf currents in March and April are all correlated with the these strong year classes. Cold winter water temperatures, low Pacific Decadal Oscillation Indices, early spring transitions and strong southward (and offshore) currents in March and April are linked to year class failure. Right now, green crabs are still too rare to exert a measurable effect on the native benthic community and on shellfish culture in Oregon and Washington. However, if their numbers were to increase, we would be able to predict the arrival of strong year classes from ocean conditions and alert managers and shellfish growers of possible increases in predation pressure from this invader.

Genomewide evidence of environmentally mediated secondary contact of European green crab (Carcinus maenas) lineages in eastern North America

“…Our finding that WinSST had the most robust relationship with ecotype distributions is consistent with the known environmental tolerances of adult green crab and their ability to grow and survive at different latitudes (Lowen, McKindsey, Therriault, & DiBacco, ). Additionally, previous studies have noted that cold winter water temperatures are linked to higher adult mortality and lower recruitment (Berrill, ; Beukema, ), while warmer winters may be linked to stronger year‐classes in green crab populations in western North America (Yamada & Kosro, ). A recent review of environmental factors influencing the local (<10 km) green crab population structure suggests that water depth and biotic interactions were the primary variables influencing distribution (Cosham, Beazley, & McCarthy, ).…”

“…Audet et al (2003) revealed that prior to the introduction of the presumably cold-adapted northern European green crab lineage, cold coastal currents appear to have halted the northward expansion of the southern green crab ecotype at approximately the latitude of Halifax, NS (~44.6°N). Similarly, cold winters in the Gulf of Maine have previously been linked to increased adult mortality whereas warm winters have been linked to increased recruitment (Yamada & Kosro, 2010). In both the native and introduced ranges, the mean high temperature at which cardiac function fails in adult crabs is consistently higher in southern populations which are adapted to overall warmer sea surface temperatures (Tepolt & Somero, 2014).…”

Reverse Estuarine Circulation Due to Local and Remote Wind Forcing, Enhanced by the Presence of Along‐Coast Estuaries

“…Connectivity between estuaries and the coastal ocean is a key dynamical driver impacting critical biological and biogeochemical processes, such as ocean/estuarine nutrient and phytoplankton exchange (e.g., Boyer et al, ; Davis et al, ), and regulation of estuarine residence time, hypoxia, and acidification (e.g., O'Callaghan et al, ). Additionally, connectivity between along‐coast (i.e., neighboring or nearby) estuaries controls larval transport and population connectivity (e.g., McConnaughey et al, ; Yamada & Kosro, ).…”

Responses of Aquatic Non-Native Species to Novel Predator Cues and Increased Mortality

“…The similarity in relative juvenile abundance across location, even as these abundances change over time, suggests removal efforts in Bodega Harbor did not affect local juvenile recruitment. The high inter-annual variability coupled with the similar relative abundances of juveniles across bays support the hypothesis that juvenile Carcinus recruitment in this region is driven not by biotic conditions unique to location, such as intraspecific pressures, but rather by regional abiotic conditions (Shanks & Roegner 2007, Yamada & Kosro 2009). This is in line with observations by Yamada & Kosro (2009), who found that recruitment of juvenile Carcinus in Oregon and Washington were correlated with a number of regional abiotic conditions including winter water temperatures in bays surveyed, timing of the spring transition (i.e., shift in wind direction along the north-eastern Pacific resulting in shift from downwelling to upwelling) and weak southward shelf currents.…”